It is important that seats which are to be located within vehicles such as aircraft and the like be suitably designed to resist the forces to which they may be subjected when the vehicle is subject to sudden stops such as would occur in a collision or a crash involving the vehicle. When a vehicle such as an aircraft or the like is subjected to a collision or a crash, the forces exerted on the seats may be extremely high in view of the speed of the vehicle and its rapid deceleration when it is involved in a collision or a crash.
In view of the forces exerted upon the seats when a vehicle such as an aircraft is involved in a collision or a crash, it is very difficult to design a suitable seat which will adequately seat the occupants during such a collision or crash. One particular problem is that the loads exerted upon the seat may be so high as to cause the seat to actually separate from the vehicle. Of course, such a situation is highly undesirable since not only does the separated seat substantially increase the risk of injury to the occupant, but in addition the separated seat can also cause injuries to others since it is detached from the aircraft. The present attaching systems for attaching aircraft seats and the like to the interior of an aircraft generally include some type of locking tracks located in the floor of the aircraft and associated locking mechanisms connected to lower ends of the legs of the aircraft seats which are designed to engage the locking tracks. Unfortunately, this type of system has a definite limit insofar as its strength and ability to survive the forces exerted upon it during a collision or crash.
In view of this situation, it is necessary to design the vehicle seat in a manner such that it will absorb or attenuate some of the energy to which it is subjected during a collision or crash so that this energy is not passed on to the seat attaching system. In particular, it is important that the vehicle seat absorb or attenuate sufficient energy so that the attaching system does not fail in order that the vehicle seat remain connected to the vehicle during a collision or a crash. The importance of providing some means of absorbing or atten-uating the energy to which a seat is subjected during a crash or an abrupt stop has been recognized in the past and some seats have been designed incorporating some type of energy absorbing attenuating apparatus. An example of such an apparatus is set forth in U.S. Patent No. 3,059,966 which discloses an aircraft seat which incorporates an energy absorbing brace. Unfortunately, the effectiveness of such a seat is limited since it is designed to only provide energy absorbing means for reducing the shock to a person resulting from downward movement of the aircraft whereas in many collisions and crashes the major concern is with an abrupt halt to forward movement of the vehicle. Moreover, the construction of the seats set forth in this patent did not readily permit it to be utilized in commercial vehicles such as aircraft.
Another example of such an apparatus is set forth in U S. Pat. No. 3,603,638 which discloses a vehicle seat which is designed to absorb energy by having a support member for the seat which is designed to bend when it is subjected to a particular load. Unfortunately, this system also relies upon some type of associated energy absorber or shock absorber unit which are associated with the bendable members. Such an energy absorbing unit may be impractical to utilize in connection with a vehicle seat and in any event would significantly increase the cost of the seat. In addition, the use of such an energy absorbing unit would increase the weight of the seat which is particularly undesirable insofar as aircraft seats are concerned.
The present invention overcomes these problems associated with previous efforts to provide vehicle seats with energy absorbing or attenuating apparatus to enable them to counteract the forces exerted upon the seat during a vehicle collision or crash. In particular, the present invention provides a vehicle seat and leg therefor which is capable of readily absorbing energy resulting from an abrupt deceleration of the vehicle primarily when the vehicle is moving in forward direction. Moreover, the present invention does not require any complex alterations of the seat and does not increase the weight of the seat. Also, this invention does not require any significant redesign of the basic seat and under suitable circumstances existing seats can be modified or retrofitted to incorporate the invention.